18 ILLINOIS NATURAL HISTORY SURVEY MANUAL 3 



I. Leaves without such veins; often glaucous 

 beneath. 



J. Buds superposed Lonicera, p. 268 



J. Buds not superposed 



Symphoricarpos, p. 265 



C. Leaf margins toothed. 



K. Decumbent shrub, rooting at the nodes 



Euonymus, p. 167 



K. Upright shrubs. 



L. Internodes with decurrent, pubescent lines 



Diervilla, p. 272 



L. Pubescence, if present, not in decurrent lines. 



M. Hollow petiole bases covering buds 



Philadelphus, p. 89 



M. Petiole bases not hollow, buds axillary. 



N. Stems squarish Euonymus, p. 167 



N. Stems round. 



O. Stipules or their minute scars present. . 



Viburnum, p. 255 



O. Neither stipules nor their scars present. 

 P. Leaves acute to acuminate at both ends 



Forestiera, p. 244 



P. Leaves rounded or cordate at the base 



Hydrangea, p. 86 



B. Leaves alternate; 1 at a node. 



Q. Leaf margins entire, neither toothed nor lobed. 



R. A pair of tendrils at the base of the petiole; spiny 

 or prickly, green vines with blue-black berries in 



axillary clusters Smilax, p. 29 



R. No tendrils at the base of the petiole. 



S. Armed with spines arising in the leaf axils 



Bumelia, p. 237 



S. Unarmed shrubs or vines. 



T. Low, creeping, or prostrate shrubs with per- 

 sistent leaves. 



U. Leaves obovate, green beneath 



Arctostaphylos, p. 227 



U. Leaves oblong to ovate, glaucous beneath 



Vaccinium, p. 229 



T. Erect shrubs, whether low or tall, or climbing 

 vines. 

 V. Leaves linear, revolute, white-puberulent 



beneath, persistent Andromeda, p. 223 



V. Leaves broad, deciduous. 



W. Leaves and bark spicy and aromatic, 



fruit a red drupe Lindera, p. 83 



W. Leaves and bark neither spicy nor aro- 

 matic. 

 X. Leaves broadly cordate, palmately 3- 



to 7-veined ; twining vines 



Aristolochia, p. 73 



